As a specific kind of planar display apparatus, TFT-LCD (Thin Film Transistor Liquid Crystal Display) is becoming more and more popular in high performance display industry, since it has got various advantages, such as small size, low power consumption, low manufacturing cost and no radiation.
A TFT-LCD comprises an array substrate, a liquid crystal layer and a colored-film substrate. First, voltage is applied to a pixel electrode on the array substrate and a common electrode on the array substrate (or the colored-film substrate) to generate electric field in the liquid crystal layer; then, transmissivity of the light passing through the liquid crystal layer is adjusted by adjusting magnitude of the electric field, so as to obtain an expected display image. However, when the electric field that is maintained in the same direction is applied to the liquid crystal layer for a long time, deterioration that is not recoverable will be caused in the liquid crystal layer. A data voltage Vdata that is input to a data line on the array substrate is required to be reversed with respect to the polarity of a common voltage Vcom that is applied to the common electrode periodically.
Currently, common driving manners for the above polarity reversal include row reversal and point reversal. Particularly, row reversal is shown in FIG. 1a, where pixel units 100 in a same row have identical polarity of data voltage Vdata, whereas pixel units 100 in adjacent rows have opposite polarities of data voltage Vdata. When turning from the frame N to frame N+1, the reversal number of the data voltage Vdata is counted by one. Point reversal is shown in FIG. 1b, where every pixel unit 100 has a different polarity of data voltage Vdata than that of each of its adjacent pixel units 100.
However, in the prior art, for pixel units 100 in a same column, no matter which manner, i.e. row reversal or point reversal, is adopted, any two pixel units 100 of two adjacent rows have different polarities, therefore, the direction of the data voltage Vdata needs to be changed frequently. For example, for a display panel constituted of M rows, N columns of pixel units 100, the data voltage Vdata has to be substantially changed for M−1 times, which will significantly increase power consumption of the display driver and thus degrade the display's performance.